scholarly journals In Situ Shear Test for Revealing the Mechanical Properties of the Gravelly Slip Zone Soil

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6531 ◽  
Author(s):  
Zongxing Zou ◽  
Qi Zhang ◽  
Chengren Xiong ◽  
Huiming Tang ◽  
Lei Fan ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Plastic Deformation ◽  
Shear Test ◽  
Slip Zone ◽  
Three Gorges Reservoir Area ◽  
Silty Clay ◽  
Sigmoid Function ◽  
In Situ Test ◽  
Deformation Stage

Slip zone soil is usually composed of clay or silty clay; in some special geological environments, it contains gravels, which make the properties of the slip zone soil more complex. Unfortunately, in many indoor shear tests, gravels are removed to meet the demands of apparatus size, and the in situ mechanical property of the gravelly slip zone soil is rarely studied. In this study, the shear mechanical property of the gravelly slip zone soil of Huangtupo landslide in the Three Gorges Reservoir area of China was investigated by the in situ shear test. The test results show that the shear deformation process of the gravelly slip zone soil includes an elastic deformation stage, elastic–plastic deformation stage, and plastic deformation stage. Four functions were introduced to express the shear constitutive model of the gravelly slip zone soil, and the asymmetric sigmoid function was demonstrated to be the optimum one to describe the relationship of the shear stress and shear displacement with a correlation coefficient of 0.986. The comparison between the in situ test and indoor direct shear test indicates that gravels increase the strength of the slip zone soil. Therefore, the shear strength parameters of the gravelly slip zone soil obtained by the in situ test are more preferable for evaluating the stability of the landslide and designing the anti-slide structures.

scholarly journals Experimental Study on Variation Law and Mechanism of Soil Shear Strength Parameters along the Slope

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yanhai Wang ◽  
Jianlin Li ◽  
Qiao Jiang ◽  
Yisheng Huang ◽  
Xinzhe Li
Keyword(s):  
Shear Strength ◽  
Direct Shear Test ◽  
Shear Test ◽  
Three Gorges Reservoir Area ◽  
Silty Clay ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Undisturbed Soil ◽  
Soil Shear Strength

Under the action of rainwater seepage, geological origin, and human activities, the soil shear strength parameters will have spatial variability along the slope direction. After collecting samples of silty clay at a slope in the Three Gorges Reservoir area as the research object, not only the large-scale direct shear test was carried out on the site but also the direct shear test, water content test, density test, and particle grading analysis test were carried out in the laboratory with the undisturbed soil. The variation law and mechanism of soil shear strength parameters along slope were studied. The results indicate the following: (1) The coefficient of variation of shear strength parameters along the slope is relatively large. With the decrease of the elevation of the test location, the cohesion value tends to be strengthened, while the friction angle tends to degrade. (2) The mechanism of the variation law of soil shear strength parameters along the slope, which is mainly due to the decrease of the elevation, the decrease of the edges and angles between the particles, and the increase of the clay content is determined. (3) The variation model of shear strength parameters along the slope is proposed, which can provide a reference for relevant projects.

scholarly journals A new development of four-point method to measure the electrical resistivity in situ during plastic deformation

Measurement ◽  
2021 ◽  
pp. 109547
Author(s):  
Saeid Saberi ◽  
Martin Stockinger ◽  
Christian Stoeckl ◽  
Bruno Buchmayr ◽  
Helmut Weiss ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Electrical Resistivity ◽  
Point Method ◽  
New Development

scholarly journals Design and Application of an In Situ Test Device for Rheological Characteristic Measurements of Liquefied Submarine Sediments

2021 ◽  
Vol 9 (6) ◽  
pp. 639
Author(s):  
Hong Zhang ◽  
Xiaolei Liu ◽  
Anduo Chen ◽  
Weijia Li ◽  
Yang Lu ◽  
...  
Keyword(s):  
Yellow River ◽  
Rheological Characteristic ◽  
Yellow River Delta ◽  
Turbidity Currents ◽  
Rheological Characteristics ◽  
Submarine Landslides ◽  
Test Device ◽  
Offshore Area ◽  
In Situ Test

Liquefied submarine sediments can easily lead to submarine landslides and turbidity currents, and cause serious damage to offshore engineering facilities. Understanding the rheological characteristics of liquefied sediments is critical for improving our knowledge of the prevention of submarine geo-hazards and the evolution of submarine topography. In this study, an in situ test device was developed to measure the rheological properties of liquefied sediments. The test principle is the shear column theory. The device was tested in the subaqueous Yellow River delta, and the test results indicated that liquefied sediments can be regarded as “non-Newtonian fluids with shear thinning characteristics”. Furthermore, a laboratory rheological test was conducted as a contrast experiment to qualitatively verify the accuracy of the in situ test data. Through the comparison of experiments, it was proved that the use of the in situ device in this paper is suitable and reliable for the measurement of the rheological characteristics of liquefied submarine sediments. Considering the fact that liquefaction may occur in deeper water (>5 m), a work pattern for the device in the offshore area is given. This novel device provides a new way to test the undrained shear strength of liquefied sediments in submarine engineering.

scholarly journals Borehole shear test and its application to saturated silty clay

2021 ◽  
Vol 643 ◽  
pp. 012003
Author(s):  
Jianmin Zhu ◽  
Yongtang Yu ◽  
Xiaowei Huang ◽  
TAO Zeng ◽  
Jianguo Zheng
Keyword(s):  
Shear Test ◽  
Silty Clay
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